Objective: To investigate the predictive value of breast cancer susceptibility gene 1 (BRCA1) and class IIIβ-tubulin protein expression in tumor tissue for the efficacy of taxol and cisplatin combined chemotherapy (TP) in stage IIIB/IV non-small cell lung cancer (NSCLC) patients.
Methods: A total of 92 stage IIIB/IV NSCLC patients were recruited with 87 patients evaluated. Bronchoscopy or lung puncture tumor biopsy samples were obtained with BRCA1 and class IIIβ-tubulin protein expression examined immunohistochemically before chemotherapy. The patients were randomly assigned to be received 4 to 6 cycles of TP chemotherapy regiments and followed up until death or lost. Response rate (RR), overall survival (OS) and time to tumor progression (TTP) were assessed.
Results: Among the 87 evaluated patients, the positive expression rates of BRCA1 and class IIIβ-tubulin were 57.5% (50/87) and 48.3% (42/87) respectively. There was no significant difference in clinical characteristics among patients with different positive expression rate. According to different expression of BRCA1 and class IIIβ-tubulin, the patients were divided into four groups: group A (low expression of both BRCA1 and class IIIβ-tubulin), group B (high expression of both BRCA1 and class IIIβ-tubulin), group C (high expression of only BRCA1) and group D (high expression of only class IIIβ-tubulin). The RR was higher in group A than other three groups (60.7%, 34.8%, 9/19 and 6/17 respectively). The OS and TTP were longer in group A than other three groups [OS: (539.4 ± 17.6) days, (267.2 ± 20.5) days, (325.6 ± 24.1) days and (283.7 ± 26.2) days respectively; TTP: (256.9 ± 28.4) days, (143.8 ± 17.6) days, (179.3 ± 19.8) days and (152.6 ± 23.5) days respectively]. There were no significant differences among the other three groups.
Conclusions: The expression level of BRCA1 and class IIIβ-tubulin in tumor tissue is probably a predictor for the efficacy of TP chemotherapy in NSCLC patients. TP chemotherapy is more suitable for the NSCLC patients with lower expression of both BRCA1 and class IIIβ-tubulin. Our study may provide a new sight for tailored chemotherapy in NSCLC patients.